Constantinople is Ezio Auditore's principal setting in Assassin's Creed: Revelations.
The game places Ezio in the Ottoman capital during the early sixteenth century. He travels there to recover Altaïr Ibn-La'Ahad's Masyaf keys, which unlock memories and information connected to the first game's Assassin Mentor. Constantinople's districts, rooftops, markets, harbors, and underground passages form the main urban environment.
The historical city was known as Constantinople during the period represented in the game. Modern usage commonly calls it Istanbul, but Istanbul became the official name of the city in the twentieth century, long after Ezio's fictional adventure.
Revelations also includes playable sections featuring Altaïr, so the game moves between Ezio's later life and earlier memories from the Levant. Constantinople therefore belongs to Ezio's timeline, while Masyaf and other locations connect the narrative to Altaïr.